1. Field of the Invention
The present invention relates generally to non-viral compositions and methods useful for the cellular delivery of one or more molecules of interest. In various embodiments, modified recombinant vault particles are described which comprise a peptide domain that enhances the permeability of the particles across the cell membranes of cells targeted for delivery. Also included in the invention is the use of the compositions as cellular delivery agents for selected molecules of interest, such as nucleic acid.
2. Description of the Related Art
Vaults are cytoplasmic ubiquitous ribonucleoprotein particles first described in 1986 that are found in all eukaryotic cells [1]. Native vaults are 12.9±1 MDa ovoid spheres with overall dimensions of approximately 40 nm in width and 70 nm in length [2,3], present in nearly all-eukaryotic organisms with between 104 and 107 particles per cell [4]. Despite their cellular abundance, vault function remains elusive although they have been linked to many cellular processes, including the innate immune response, multidrug resistance in cancer cells, multifaceted signaling pathways, and intracellular transport [5].
Vaults are highly stable structures in vitro, and a number of studies indicate that the particles are non-immunogenic [6]. Vaults can be engineered and expressed using a baculovirus expression system and heterologous proteins can be encapsulated inside of these recombinant particles using a protein-targeting domain termed INT for vault INTeraction. Several heterologous proteins have been fused to the INT domain (e.g. fluorescent and enzymatic proteins) and these fusion proteins are expressed in the recombinant vaults and retain their native characteristics, thus conferring new properties onto these vaults [7,8].
Vaults are generally described in U.S. Pat. No. 7,482,319, filed on Mar. 10, 2004; U.S. application Ser. No. 12/252,200, filed on Oct. 15, 2008; International Application No. PCT/US2004/007434, filed on Mar. 10, 2004; U.S. Provisional Application No. 60/453,800, filed on Mar. 20, 2003; U.S. Pat. No. 6,156,879, filed on Jun. 3, 1998; U.S. Pat. No. 6,555,347, filed on Jun. 28, 2000; U.S. Pat. No. 6,110,740, filed on Mar. 26, 1999; International Application No. PCT/US1999/06683, filed on Mar. 26, 1999; U.S. Provisional App. No. 60/079,634, filed on Mar. 27, 1998; and International Application No. PCT/US1998/011348, filed on Jun. 3, 1998. Vault compositions for immunization against chlamydia genital infection are described in U.S. application Ser. No. 12/467,255, filed on May 15, 2009. The entire contents of these applications are incorporated by reference in their entirety for all purposes.